Bird spotters flying high with military spy cameras

Images from a military-grade satellite camera are so sharp that scientists can count the number of birds nesting on a remote rocky outcrop in  the ocean 680 kilometres south of New Zealand from high in space.

Threatened Northern Royal albatrosses nest on high cliffs on two sea stacks in the island group.

The place is so remote that even if scientists can beat the weather and navigate dangerous reefs to reach the stacks, they then have a 50 metre cliff climb to reach the top.

But the DigitalGlobal Worldview Satellite can spot features in an image a small as 30 centimetres in size from miles above in Earth orbit.

The satellite was built to provide data for the US government military and security forces.

Close up pictures from space

From space, the team monitoring the birds counted 3,600 nests on the stacks from analysing white dots on high-resolution images.

Each white dot was a nesting bird

“Getting the people, ships or planes to these islands to count the birds is expensive, but it can be very dangerous as well,” explained Dr Peter Fretwell from the British Antarctic Survey.

The survey can only access the images thanks to the US government declassifying the satellite so the images can be used outside the intelligence and military communities.

“The breeding numbers we counted were much lower than we anticipated, which could show us that the population is declining or it could show just that we had a particularly poor year,” said Dr Fretwell.

“This illustrates why you have to do this over several years, and doing it by satellite is a lot cheaper and more efficient.”

Thermal imaging reveals migration secrets

Elsewhere, technology is helping ornithologists find out more about the secrets and habits of migrating birds.

A team has deployed thermal imaging cameras around the Spanish coast on the Bay of Biscay to detect how birds navigate a migration corridor across Europe.

The cameras capture the flight paths of flocks or individual birds crossing the migratory route at night.

Scientists can count the numbers and identify some species from the flight patterns.